The present invention relates to surface finishes for pathways, walls, swimming pools and other structures and more particularly relates to a surface finish which is of a cementitious nature and which includes at least one aggregate type comprising glass beads. More particularly, the invention relates to a mix forming and to a method of producing the finishes.
In the building industry there has been prolific use of aggregate surfaces for paving footpaths, surfacing of prefabricated building panels and slabs to provide attractive and functional facades and in and around swimming pools and the like. The known aggregate mixes have invariably utilized aggregate materials which include stones, pebbles and the like mixed in a matrix of cementitious material selected from cement or resin.
The selection of pebbles and stones as the aggregate material usually dictates the appearance of the finish particularly with respect to its color and texture. When resins are used, the aggregate provides the final surface coloration as the cementitious resins are generally clear. An alternative surface coating may be formed by using colored mortar with pebbles and stones.
Despite the use of a wide range of aggregates to produce a variety of surface finishes successfully preparing a cementitious surface matrix using as the aggregate material glass beads either alone or with another aggregate materials selected from precious or semi-precious stones, sands, quartz, marble, granites and the like has been difficult to achieve. It was previously thought to be unsatisfactory to attempt to use other than conventional aggregates in hard wearing surface finishes as the bonding achieved was inferior compared with conventional aggregates. In the building industry it has been considered unwise to use materials such as glass beads as aggregates as the glass is generally considered to be insufficiently porous or rough enough to establish an effective bond. The bond is also compromised by alkalinity bleed out from the glass beads.
The present invention overcomes the effective use of alternative aggregates and particularly glass beads in which the problems of poor bonding known in the prior art aggregates is overcome.
In the broadest form of the apparatus aspect the present invention comprises; a surface finish for application to a vertical horizontal or sloping surface/s of a structure or object which provides a substrate for said surface finish, the surface finish comprising; a matrix formed from a combination of at least a cementitious material, water, glass beads of either the same or different sizes and an adhesive.
In the preferred embodiment, the surface finish comprises a blended matrix of cementitious mortar, an aggregate of glass beads of the same or different sizes used alone or in conjunction with other aggregates selected from precious stones, semiprecious stones or raw stones and liquid adhesive comprising a combination of a silicone and a concrete fortifier for enhancing the bond between the cementitious mortar and glass beads.
The finish may be applied to the surface of a structure such as a building facade, as a paving surface or simply to almost any object formed from a material capable of forming a bond with the finish.
The consistency and/or blend of the matrix may be varied according to the nature of the substrate surface to which the surface coating is applied. Thus the mix will vary according to whether or not the surface is horizontal, vertical or sloped and according to the type of material which forms the substrate. For instance, application of the finish to a vertical surface requires the mix to bind to the surface and this is achieved by ensuring that the mix assumes the right paste consistency.
According to the method aspect, the present invention also provides a method of preparing a surface finish comprising the steps of, a) mixing a cementitious mortar with water and a liquid or powdered adhesive, b) introducing glass beads into the mix alone or with another aggregate, c) blending the mix for a pre-selected duration until the mix reaches a predetermined consistency, d) applying the mix to a substrate surface of a structure or other object, e) allowing the mix to soft set, f) exposing a predetermined surface area of the beads by either washing or sponging the surface of the finish with water; or g) allowing the mix to hard set and washing with hydrochloric acid.
In the broadest form of the method aspect, the present invention comprises a method for producing a surface finish on the surface of a structure or other object as hereinbefore described comprising the steps of; a) selecting a cementitious material, b) selecting glass beads from within the size range of 0.1 mm to 200 mm, c) adding an adhesive to the mix, d) mixing the cementitious material with the selected bead sizes and water until the mix reaches a predetermined consistency, e) applying the matrix so formed to the surface of a structure, f) washing away part of the cementitious material such that 30-60% of the surface area of a substantial number of the glass beads on the surface of the matrix is exposed, g) allowing the surface finish to set.
According to the preferred embodiment of the method aspect the adhesive comprises a silicone and a concrete fortifier mixed together.
According to a preferred embodiment the aggregate bead/cement ratio is 5:8 or five part beads to 3 parts cement. Alternatively, the bead/cement ratio may be 8:5.